tests: add some missing #if's / hghave requirements

Seen on Linux with FAT.

tests/test-convert-baz.t

@@ -1,4 +1,4 b''
-  $ "$TESTDIR/hghave" baz || exit 80
+  $ "$TESTDIR/hghave" baz symlink || exit 80
 
   $ baz my-id "mercurial <[e-mail]>"
 

tests/test-convert-cvsnt-mergepoints.t

@@ -91,6 +91,8 b' script)'
   $ echo xyzzy > foo.txt
   $ cvsci -m "merge1+clobber" foo.txt
 
+#if unix-permissions
+
 return to trunk and merge MYBRANCH1_2
 
   $ cvscall -Q update -P -A
@@ -200,5 +202,6 b' return to trunk and merge MYBRANCH1_2'
   Members: 
   	foo.txt:1.1.4.1->1.1.4.2 
   
+#endif
 
   $ cd ..

tests/test-merge-tools.t

@@ -277,6 +277,8 b' and true.executable set to cat with path'
   # hg stat
   M f
 
+#if unix-permissions
+
 environment variables in true.executable are handled:
 
   $ echo 'echo "custom merge tool"' > "$HGTMP/merge.sh"
@@ -300,6 +302,8 b' environment variables in true.executable'
   # hg stat
   M f
 
+#endif
+
 Tool selection and merge-patterns
 
 merge-patterns specifies new tool false:

tests/test-transplant.t

@@ -356,6 +356,8 b' test transplant into empty repository'
   $ cd ..
 
 
+#if unix-permissions system-sh
+
 test filter
 
   $ hg init filter
@@ -443,6 +445,9 b' test transplant with filter handles inva'
   [255]
   $ cd ..
 
+#endif
+
+
 test with a win32ext like setup (differing EOLs)
 
   $ hg init twin1

tests/test-walk.t

@@ -276,9 +276,11 b' Test patterns:'
   $ hg debugwalk NOEXIST
   NOEXIST: * (glob)
 
+#if fifo
   $ mkfifo fifo
   $ hg debugwalk fifo
   fifo: unsupported file type (type is fifo)
+#endif
 
   $ rm fenugreek
   $ hg debugwalk fenugreek